journeyman

One who has fully served an apprenticeship in a trade or craft and is a qualified worker in another's employ.

An experienced and competent but undistinguished worker.

In astronomy, a secondary clock in an observatory: used, generally, as an intermediary in the comparison of standard clocks: more fully, journeyman clock.

A man hired to work by the day; a day-worker.

A workman or mechanic who has served his apprenticeship; specifically, a qualified mechanic employed in the exercise of his trade, as distinguished from a master mechanic or a foreman.